Field of the Disclosure
Embodiments of the disclosure generally relate to a locking collar quick union connection.
Description of the Related Art
Quick union connections are typically used to connect different components of various types of oilfield equipment. Quick union connections usually have a collar with ACME threads (e.g. standard, stub, or modified threads) that is threaded to a mating component. The threads are not pre-loaded when initially assembled, but rather, when the oilfield equipment is placed under pressure, the quick union connection is subjected to an axial load that loads the threads in the axial direction.
However, when the oilfield equipment that is connected together with the quick union connection is subject to a high vibration environment (such as when conducting a fracturing operation using the oilfield equipment), the harmonics of the vibrations induce a radial acceleration that may loosen the quick union connection. In particular, the collar of the quick union connection tends to “back out” and unthread from the mating component, thereby loosening the threaded connection. This loosening of the threaded connection compromises the fluid containment capabilities of the quick union connection and the oilfield equipment, as well as the safety of personnel working near the oilfield equipment and other equipment operating nearby.
Prior methods of using straps to hold down the oilfield equipment, replacing the quick union connection with a bolted flange connection, or axially loading the threads by pressure loading the quick union connection have numerous disadvantages. The use of multiple straps to physically strap down the oilfield equipment creates more work and can actually become a hazard to personnel working near the oilfield equipment. The use of bolted flange connections increases the amount of time needed to assemble and disassemble the connection due to additional tooling and the alignment of the oilfield equipment that is necessary to assemble and disassemble the bolted flange connection. Furthermore, bolted flange connections cannot retrofit to existing oilfield equipment and would require a complete change out of equipment. Axially loading the threads by pressurizing the connection is done by trial and error as the pressure required to produce the axial load required to prevent vibration backoff varies with the various configurations of oilfield equipment/applications.
Therefore, there is a need for new and improved quick union connections.